The so-called "iPhone 6s" and "iPhone 6s Plus" will reportedly adopt Force Touch, a feature that debuted on the Apple Watch in September, according to sources for AppleInsider. The next-generation iPhones are expected to retain the same physical design as the iPhone 6 and iPhone 6 Plus, including 4.7-inch and 5.5-inch models. The report adds that the return of a 4-inch model appears unlikely for this refresh.

Force Touch uses tiny electrodes to distinguish between a light tap or deep press on the screen, prompting the software to perform a different action depending on how much pressure is exerted on the display. Apple would likely have to use a flexible OLED display on a future iPhone model in order for Force Touch to be possible on the smartphone. Apple calls Force Touch its most significant new sensing capability since Multi-Touch on its Apple Watch microsite.

"In addition to recognizing touch, Apple Watch senses force, adding a new dimension to the user interface. Force Touch uses tiny electrodes around the flexible Retina display to distinguish between a light tap and a deep press, and trigger instant access to a range of contextually specific controls — such as an action menu in Messages, or a mode that allows you to select different watch faces — whenever you want. It’s the most significant new sensing capability since Multi‑Touch."

Apple reportedly experimented with adding Force Touch to the iPhone 6 and iPhone 6 Plus last year, although calibration issues resulted in removal of the feature prior to the smartphones being released. The issues appear to have been resolved at this point, however, and Force Touch is now on Apple's upcoming roadmap. The so-called "iPhone 6s" and "iPhone 6s Plus" will presumably be announced next September.

The report also dismisses the rumor about next-generation iPhones gaining a DSLR-like dual-lens camera system, as implementing this feature would require redesigning the iPhone and moving away from the current chassis found on the iPhone 6 and iPhone 6 Plus. Last month, it was reported that the iPhone 6s will retain an 8-megapixel rear-facing camera sensor, although that does not limit other improvements from being made.